So I have a C program to interface with an i2c device. I need to interface to that device from python. I'm just wondering if it's worth porting the program into a python module or if the amount of effort involved in porting won't outweigh just executing the program using subprocess. I know I'm sure it's different for every application, but I'd like to know if it's even worth my time to learn the python C extensions and port this program.
Update: I have full access to the source of both the C as well as the python. But there is already substantial work done on the python side and I'd like to keep changes to that as minimal is possible, if that matters. And I'd also like to minimize the changes that have to be made to the C. It's doable, but I didn't write it and it involves a lot of by addressing that I'd rather not have to redo.
There are many ways you can proceed -- the Python C API, which seems to be the one you're considering, but also SWIG, Cython, ctypes... as long as your existing C code can be made into a library (with functions callable "from the outside"), you have a wealth of options. Personally, I'd recommend Cython -- it's looking more and more as a broad subset of Python, extended just enough to allow effective compilation into machine code and direct calling of functions from C libraries.